Anatomical basis and design of the distally based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone: a cadaveric dissection.

Background: Detailed investigation of the vasculature of the lateral aspect of the foot has rarely been presented. However, harvesting the flap in this area to cover defects of the foot and hand is highly important. Repair of soft-tissue defects at the forefoot remains a challenge in reconstructive surgery. This study explores the characteristics of the distal-based lateral dorsal cutaneous neuro-lateral plantar venofasciocutaneous flap pedicled with the lateral plantar artery perforator of the fifth metatarsal bone to establish a repair procedure for ulcers or defects in the forefoot region.

Methods: This study is divided into two parts: anatomical study and simulated operation. Thirty cadavers were utilized in the anatomical study after arterial injection. The tuberosity of the fifth metatarsal bone was used as the anatomical landmark. The lateral plantar artery perforator of the fifth metatarsal bone was identified through dissection. The perforators were dissected under a microscope. The details of the lateral plantar artery perforators, the distribution of the lateral dorsal cutaneous nerve and lateral plantar vein, the anastomosis in the lateral plantar artery perforator of the fifth metatarsal bone, the nutrient vessels of the lateral dorsal cutaneous nerve and lateral plantar vein, and other arteries of the lateral foot were recorded. The flap-raising procedure was performed on three fresh cadavers.

Results: The lateral dorsal cutaneous nerve originated from sural nerve, traveled obliquely downward along the anterior lateral margin of the foot, and accompanied by the lateral plantar vein after bifurcation, and was eventually distributed on the lateral aspect of the foot. The nutrifying arteries to the lateral dorsal cutaneous nerve and lateral plantar vein were present segmentally and mainly originated from the lateral plantar artery perforator of the fifth metatarsal bone. These nitrifying arteries constantly originated from the lateral plantar artery in the area of tuberosity of the fifth metatarsal, ran along the medial side of the fifth metatarsal, traveled between the fifth metatarsal bone and the lateral muscle group (the flexor digitorum brevis and the abductor digiti minimi muscles), pierced the aponeurosis, vascularized the skin of the anterior lateral plantar region, and resulted in many minute branches, which anastomosed with the lateral tarsal artery and fourth dorsal metatarsal artery. The anatomical study showed that (1) the vasculature pattern can roughly be classified into three types and (2) constant anastomoses occurred between the above-mentioned arteries in the lateral-dorsum region of the foot.

Conclusion: A reliable large- or medium-sized neuro-venocutaneous flap with lateral dorsal cutaneous nerve, lateral plantar vein, and nutrient vessels can be raised using only the perforator of the lateral plantar artery of the fifth metatarsal bone, which is thin, is in the immediate vicinity of the forefoot, and has a reliable retrograde blood supply. This flap can be considered an alternative means to reconstruct soft-tissue defects of the forefoot.